For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningSafety Locks
The rear door safety locks prevent passengers from opening the rear doors from
inside the vehicle.
Press to activate the safety locks.
The indicator light comes on when activated.
The rear door power windows are also disabled.
Press again to deactivate the safety
locks and power windows ...
Steering Gear Replacement (Hydraulic Power Steering)
Special Tools
EN 45059 Torque Angle Sensor Kit
For equivalent regional tools, refer to Special Tools.
Removal Procedure
Turn the front wheels to the straight forward position and secure the
steering wheel from moving.
Remove the lower steering intermediate shaft bolt (1).
...
Front Side Door Window Replacement
Preliminary Procedure
Position the window approximately half way down in the door.
Remove the water deflector. Refer to Front Side Door Water Deflector
Replacement.
Remove the outer sealing strip. Refer to Front Side Door Window Outer
Sealing Strip Replacement.
Fr ...